<template>
  <div class="top-nav-container">
    <span class="system-title">{{ title }}</span>
    <el-menu :default-active="activeMenu" mode="horizontal" @select="handleSelect">
      <template v-for="(item, index) in topMenus">
        <el-menu-item :style="{ '--theme': theme }" :index="item.path" :key="index" v-if="index < visibleNumber">
          <!-- <svg-icon :icon-class="item.meta.icon" /> -->
          <span>{{ item.meta.title }}</span>
        </el-menu-item>
      </template>

      <!-- 顶部菜单超出数量折叠 -->
      <el-submenu :style="{ '--theme': theme }" index="more" v-if="topMenus.length > visibleNumber">
        <template slot="title">更多菜单</template>
        <template v-for="(item, index) in topMenus">
          <el-menu-item :index="item.path" :key="index" v-if="index >= visibleNumber">
            <!-- <svg-icon v-if="!item.meta.icon || item.meta.icon !== '#'" :icon-class="item.meta.icon" />  -->
            {{ item.meta.title }}
          </el-menu-item>
        </template>
      </el-submenu>
    </el-menu>
  </div>
</template>

<script>
import { constantRoutes } from '@/router'

// 隐藏侧边栏路由
const hideList = ['/index', '/user/profile']

export default {
  data() {
    return {
      title: process.env.VUE_APP_TITLE,
      // 顶部栏初始数
      visibleNumber: 7,
      // 当前激活菜单的 index
      currentIndex: undefined
    }
  },
  computed: {
    theme() {
      return this.$store.state.settings.theme
    },
    // 顶部显示菜单
    topMenus() {
      let topMenus = []
      this.routers.map(menu => {
        if (menu.hidden !== true) {
          // 兼容顶部栏一级菜单内部跳转
          if (menu.path === '/') {
            topMenus.push(menu.children[0])
          } else {
            topMenus.push(menu)
          }
        }
      })
      return topMenus
    },
    // 所有的路由信息
    routers() {
      return this.$store.state.permission.topbarRouters
    },
    // 设置子路由
    childrenMenus() {
      var childrenMenus = []
      this.routers.map(router => {
        for (var item in router.children) {
          if (router.children[item].parentPath === undefined) {
            if (router.path === '/') {
              router.children[item].path = '/' + router.children[item].path
            } else {
              if (!this.ishttp(router.children[item].path)) {
                router.children[item].path = router.path + '/' + router.children[item].path
              }
            }
            router.children[item].parentPath = router.path
          }
          childrenMenus.push(router.children[item])
        }
      })
      return constantRoutes.concat(childrenMenus)
    },
    // 默认激活的菜单
    activeMenu() {
      const path = this.$route.path
      let activePath = path
      if (path !== undefined && path.lastIndexOf('/') > 0 && hideList.indexOf(path) === -1) {
        const tmpPath = path.substring(1, path.length)
        activePath = '/' + tmpPath.substring(0, tmpPath.indexOf('/'))
        if (!this.$route.meta.link) {
          this.$store.dispatch('app/toggleSideBarHide', false)
        }
      } else if (!this.$route.children) {
        activePath = path
        this.$store.dispatch('app/toggleSideBarHide', true)
      }
      this.activeRoutes(activePath)
      return activePath
    }
  },
  beforeMount() {
    window.addEventListener('resize', this.setVisibleNumber)
  },
  beforeDestroy() {
    window.removeEventListener('resize', this.setVisibleNumber)
  },
  mounted() {
    this.setVisibleNumber()
  },
  methods: {
    // 根据宽度计算设置显示栏数
    setVisibleNumber() {
      const width = document.body.getBoundingClientRect().width / 3
      this.visibleNumber = parseInt(width / 85)
    },
    // 菜单选择事件
    // 菜单选择事件
    /**
     * index: 选中菜单项的 index,
     * indexPath: 选中菜单项的 index path
     */
    handleSelect(key, keyPath) {
      this.currentIndex = key
      const route = this.routers.find(item => item.path === key)
      //修改为完全隐藏左侧菜单
      if (this.ishttp(key)) {
        // http(s):// 路径新窗口打开
        window.open(key, '_blank')
      } else if (!route || !route.children) {
        // 没有子路由路径内部打开
        this.$router.push({ path: key })
        this.$store.dispatch('app/toggleSideBarHide', true)
      } else {
        /**
         * 处理点击顶部菜单，默认跳转第一个子菜单
         * 最多支持三级菜单
         */
        // 显示左侧联动菜单
        this.activeRoutes(key)
        // 获取第一个未隐藏的子路由
        for (let i = 0; i < route.children.length; i++) {
          if (route.children[i].hidden == false) {
            let firstUnHiddenChild = route.children[i]
            // 跳转到第一个未隐藏的子路由
            // 该路由仍包含子路由，需要再切一层
            if (firstUnHiddenChild.children != null) {
              for (let j = 0; j < firstUnHiddenChild.children.length; j++) {
                //找到第一个未隐藏的子路由
                if (firstUnHiddenChild.children[j].hidden == false) {
                  let firstUnHiddenChildTmp = firstUnHiddenChild.children[j]
                  //第三层路由path只有最后的路径，需要拼接父路由的路径
                  this.$router.push({
                    path: path.resolve(firstUnHiddenChild.path, firstUnHiddenChildTmp.path),
                    query: firstUnHiddenChildTmp.query == undefined ? null : JSON.parse(firstUnHiddenChildTmp.query)
                  })
                  break
                }
              }
            } else {
              //该路由不包含子路由，即只有两级菜单，直接跳转
              this.$router.push({
                path: firstUnHiddenChild.path,
                query: firstUnHiddenChild.query == undefined ? null : JSON.parse(firstUnHiddenChild.query)
              })
            }
            break
          }
        }
        this.$store.dispatch('app/toggleSideBarHide', false)
      }
    },

    // 当前激活的路由
    activeRoutes(key) {
      var routes = []
      if (this.childrenMenus && this.childrenMenus.length > 0) {
        this.childrenMenus.map(item => {
          if (key == item.parentPath || (key == 'index' && '' == item.path)) {
            routes.push(item)
          }
        })
      }
      if (routes.length > 0) {
        this.$store.commit('SET_SIDEBAR_ROUTERS', routes)
      } else {
        this.$store.dispatch('app/toggleSideBarHide', true)
      }
    },
    ishttp(url) {
      return url.indexOf('http://') !== -1 || url.indexOf('https://') !== -1
    }
  }
}
</script>

<style lang="scss">
.system-title {
  font-size: 26px;
  font-weight: bold;
  margin-right: 15px;
  line-height: 22px;
}
.top-nav-container {
  display: flex;
  align-items: center;
}
.el-menu--horizontal > .el-menu-item {
  height: 65px !important;
  line-height: 65px !important;
  font-size: 16px !important;
  box-sizing: border-box;
}
.topmenu-container.el-menu--horizontal > .el-menu-item {
  float: left;
  height: 65px !important;
  line-height: 65px !important;
  color: #999093 !important;
  padding: 0 5px !important;
  margin: 0 10px !important;
  font-size: 16px !important;
}

.topmenu-container.el-menu--horizontal > .el-menu-item.is-active,
.el-menu--horizontal > .el-submenu.is-active .el-submenu__title {
  border-bottom: 2px solid #{'var(--theme)'} !important;
  box-sizing: border-box;
  color: #303133;
}

/* submenu item */
.topmenu-container.el-menu--horizontal > .el-submenu .el-submenu__title {
  float: left;
  height: 65px !important;
  line-height: 65px !important;
  color: #999093 !important;
  padding: 0 5px !important;
  margin: 0 10px !important;
}
.el-menu--horizontal > .el-submenu .el-submenu__title {
  height: 65px !important;
  line-height: 65px !important;
  font-size: 16px;
}
.el-menu.el-menu--horizontal {
  border: none !important;
}
</style>
